ref: 4b9ccb2de0466dd3cabc50b2e8e9d709b94d9bb9 dir: /sys/src/libc/arm64/argv0.s/
GLOBL argv0(SB), $8 GLOBL _tos(SB), $8 GLOBL _privates(SB), $8 GLOBL _nprivates(SB), $4